Enable SharedFunctionInfo-based tier-up.

Set flag --mark-shared-functions-for-tier-up to true.

R=leszeks@chromium.org

Review-Url: https://codereview.chromium.org/2694363006
Cr-Commit-Position: refs/heads/master@{#43272}

src/flag-definitions.h

@@ -270,7 +270,7 @@ DEFINE_IMPLICATION(ignition_staging, validate_asm)
 // Flags for experimental implementation features.
 DEFINE_BOOL(allocation_site_pretenuring, true,
             "pretenure with allocation sites")
-DEFINE_BOOL(mark_shared_functions_for_tier_up, false,
+DEFINE_BOOL(mark_shared_functions_for_tier_up, true,
             "mark shared functions for tier up")
 DEFINE_BOOL(page_promotion, true, "promote pages based on utilization")
 DEFINE_INT(page_promotion_threshold, 70,